Orion System RNE Modular Controller - Manual (Page 59)

RNE Modular Controller Field Technical Guide
SEQUENCE OF OPERATION
59
AAON ® MODGAS-X Controller
The AAON ® MODGAS-X Controller is treated as a single stage of gas
heating when connected to the RNE’s expansion port. The Supply Air
Temperature is broadcast from the AAON
®
MODGAS-X Controller to
the RNE. The Supply Air Temperature Setpoint is broadcast from the
RNE to the AAON
®
MODGAS-X Controller. When the RNE enters
the Heating Mode, it broadcasts a command to activate the MODGAS
Controller. The AAON
® MODGAS-X Controller modulates the Natural
Gas Valve to maintain the Supply Air Temperature Setpoint. See the
MODGAS-X Controller Technical Guide for detailed operation informa-
tion of the AAON
®
MODGAS-X Controller.
AAON ® MODGAS-X Controller with Additional
Stages of Heat
The RNE can activate the AAON ® MODGAS-X Controller and ad-
ditional stages of heating if needed. If this confi guration is needed, a
heating relay must be confi gured on the RNE for the AAON
®
MODGAS-
X Controller, but it will not be connected to anything. The AAON
®
MODGAS-X Controller will always be the fi rst stage of heating in this
confi guration. Additional heating relays can be confi gured and con-
nected to Staged Heating sources, such as Natural Gas or Electric Heat.
In order for the additional stages to activate, the AAON
®
MODGAS-X
Controller must be at 100%, and then the Stage Up Delay begins. Once
the Stage Up Delay expires and the Gas Valve is still at 100%, another
Fixed Stage of Heating will activate. This will be the RNE’s second
stage of heat. The AAON
® MODGAS-X Controller will modulate to
achieve the Active Supply Air Temperature Setpoint.
If the AAON
®
MODGAS-X Controller modulates to 0% and the Sup-
ply Air Temperature is above the Active Supply Air Setpoint plus the
Heating Stage Control Window, the Stage Down Delay begins. Once
the Stage Down Delay expires and the Supply Air Temperature has
remained above the Active Supply Air Setpoint plus the Heating Stage
Control Window, the Fixed Stage of Heating will be deactivated. The
AAON
®
MODGAS-X Controller will remain active, even at the mini-
mum valve position unless the Supply Air Temperature remains above
the Active Supply Air Setpoint plus the Heating Stage Control Window.
The AAON
®
MODGAS-X Controller will be the last stage of heating
to be deactivated.
Modulating Heating
The RNE supports various forms of Modulating Heat such as SCR
Electric Heat, Modulating Hot Water Heat, and Modulating Steam Heat.
Whichever form of Modulating Heating is used, the RNE will modulate
the Heat Source to achieve the Active Supply Air Temperature Setpoint.
Modulating Natural Gas is a form of Modulating Heat, but is controlled
by the AAON
®
MODGAS Controller. The RNE only activates the
AAON ® MODGAS as a stage of heat; therefore, the Modulating Heat-
ing Proportional Window does not apply when the RNE is connected
to the AAON
®
MODGAS Controller and is the only form of Heating
activated by the RNE.
The Modulating Heating Proportional Window is used to determine the
signal to the Modulating Heating Source and is user-adjustable. The
Modulating Heating Signal is calculated by the differential between
the Supply Air Temperature and the Active Supply Air Temperature
Setpoint based on the Modulating Heating Proportional Window. The
maximum signal adjustment per Time Period is 10% and is not user-
adjustable. The minimum signal adjustment per Time Period is based on
the Modulating Heating Proportional Window. The larger the Modulating
Heating Proportional Window, the smaller the signal adjustment will be
per Time Period. The Time Period is the delay between another increase
or decrease in the Modulating Heating source signal and is user-adjust-
able. For example, if the Modulating Heating Proportional Window is
5°F, the signal will be adjusted 2% per °F each Time Period above or
below the Active Supply Air Temperature Setpoint. When the Supply
Air Temperature is above or below the Active Supply Air Temperature
Setpoint by 5°F or more, the signal will adjust 10% each Time Period.
The RNE can activate two forms of Heating that are classifi ed as Primary
and Secondary Heat Sources. The Primary Heat Source used can be
SCR Electric Heat, Modulating Hot Water Heat, or Modulating Steam
Heat. The Secondary Heat Source used can be Modulating Natural
Gas (AAON
® MODGAS-X Controller), Staged Gas Heat, or Staged
Electric Heat.
Primary Modulating Heat and Secondary Heat with
AAON
®
MODGAS-X Controller
The Modulating Heating Proportional Window is used to determine the
signal to the Primary Heat Source and is user-adjustable. The Heating
Stage Control Window is used to determine stage up and stage down
of the Secondary Heat Source. In the Heating Mode, the Primary Heat
Source will modulate to achieve the Active Supply Air Temperature
Setpoint. When the Primary Heat Source reaches 100%, the Heating
Stage Up Delay begins. If the Primary Heat Source is still at 100% after
the Heating Stage Up Delay expires, the Secondary Heat Source, which
is controlled by the AAON
®
MODGAS-X Controller, will activate. The
Primary Heat Source will then be forced to 0%, allowing the AAON
®
MODGAS-X Controller to modulate the gas valve to achieve the Active
Supply Air Temperature Setpoint.
When the Secondary Heat Source reaches 100%, the Heating Stage Up
Delay begins. If the Secondary Heat Source is still at 100% after the
Heating Stage Up Delay expires, the Primary Heat Source will be forced
to 100%. The Primary Heat Source will remain at 100% to allow the
Secondary Heat Source to modulate to achieve the Active Supply Air
Temperature Setpoint. If the Supply Air Temperature rises above the
Active Supply Air Temperature Setpoint plus the Heating Stage Control
Window, the Heating Stage Down Delay begins. If the Supply Air Tem-
perature is still above the Active Supply Air Temperature Setpoint plus
the Heating Stage Control Window and the Heating Stage Down Delay
expires, the Primary Heat Source will forced to 0%. If the Secondary
Heat Source modulates to 0%, the Heating Stage Down Delay begins. If
the Secondary Heat Source remains at 0% and the Heating Stage Down
Delay expires, the Secondary Heat Source will be deactivated, and the
Primary Heat Source will modulate to achieve the Active Supply Air
Temperature Setpoint. If the Supply Air Temperature rises above the
Active Supply Air Temperature Setpoint plus the Heating Stage Control
Window, the Primary Heat Source modulates as needed to allow the
Supply Air Temperature to cool off.
Heating Mode